Officials in both parties were watching for signs of a protest. Jennifer Winn is the owner of a Wichita-area property management firm, and her platform included legalizing marijuana.

They had agreed that a single challenge was likely to receive about 20 percent of the vote under any circumstances.

But Brownback is facing a tougher-than-expected race from Democratic challenger Paul Davis because of questions about whether massive personal income tax enacted at the governor's urging are boosting the economy as he had promised or wrecking the state's finances.